Matthew Okenyi

Project title: Mesoscopic size effects on organic ferroelectrics

Supervisors: Dr Laura Ratcliff and Prof Aron Walsh

Project description:The recently discovered family of organic ferroelectric materials could become a cheaper, more environmentally friendly alternative to inorganic ferroelectrics such as barium titanate and potassium zirconate titanate for applications in optics, actuation, memory chips, and temperature sensing devices [1]. The majority of theoretical studies that have been carried out so far on organic ferroelectrics have focused on bulk properties e.g. [2, 3]; however, to accurately predict their potential, it is necessary to understand the impact of domains, grains and other defects on their ferroelectric, piezoelectric, and optical properties, similarly to how inorganic ferroelectrics have been investigated e.g. in [4].

The aim of this project is to develop theoretical and computational tools to efficiently simulate these mesoscopic size effects so that they can be fully understood and manipulated. We will carry out ab initio electronic structure and molecular dynamics calculations to understand the microscopic mechanisms that underpin the polarization switching and phase transitions of a range of organic ferroelectrics such as croconic acid [5]. These will then be used to parametrize computationally efficient models so that the mesoscopic size effects of interest can be captured.